Bogdan,

Thanks for the reminder, this is a question that I don't know the answer, as I'm struggling to understand the whole configuration. I will try to find out why it is called:).

BTW, I always want to see if I can make SER a powerful server with following configuration:

1. Check if SIP end point(base on the SIP message, like Register, Invite) is behind the NAT, if it is with private IP, then use SER NAThelper for SIP Message and RTP Proxy for RTP. 2. If it is with public IP, check if its IP and Source port is as claimed in the SIP Message(Invite, Register, etc), if yes, then proceed to treat this SIP end point with public IP. 3. If 2 is not true, then this end point may use STUN with wrong detection result, then we treat it as in 1.

I wonder if there is any sample configurations for reference?

Best Regards, Bill Zhang Tel: 626-956-0260 ext 601 Cell: 626-354-0967 web: www.grandstream.com email: wzhang@grandstream.com

-----Original Message----- From: Bogdan-Andrei Iancu [mailto:bogdan@voice-system.ro] Sent: Friday, August 04, 2006 8:16 AM To: Bill Zhang Cc: 'Marc Haisenko'; users@openser.org Subject: Re: [Users] Can not register to OPENSER

Hi Bill,

you should you call force_rtp_proxy() for a REGISTER?

regards, bogdan

Bill Zhang wrote:

The issue is, this is a SIP Registration message, it certainly does NOT contain SDP, in fact there are other SIP messages that does NOT contain SDP message but still need nathelper to recognize it behind a NAT so that OPENSER can send response back to the client correctly.

In summary, nathelper should be able to base on the SIP message to handle

it

correctly.

Best Regards, Bill Zhang -----Original Message----- From: Marc Haisenko [mailto:haisenko@comdasys.com] Sent: Thursday, August 03, 2006 12:09 AM To: users@openser.org Cc: Bill Zhang Subject: Re: [Users] Can not register to OPENSER

On Thursday 03 August 2006 00:46, Bill Zhang wrote:

...

Anyone knows why I keep getting following error message?

Aug 2 13:10:26 localhost openser[30695]: ERROR: extract_body: message

body

...

has length zero

Aug 2 13:10:26 localhost openser[30695]: ERROR: force_rtp_proxy2: can't extract body from the message

The message says it, and your SIP message proves it: the SIP message has no

body.

nathelper operates on the SDP body, it mangles them (together with

rtpproxy)

so that the SDP body sent to the receiver contains the address of your machine running OpenSER instead of the real phone. This is so that the machine can act as RTP proxy on network edges.

Since your SIP message has no SDP body there is nothing nathelper can do

:-)

C'ya, Marc